Preschool booster coverage in the study cohort was 91.4%. After adjustment for other variables, uptake was associated most strongly with completed primary immunisation for diphtheria, tetanus, and polio vaccine or first dose measles, mumps, and rubella vaccine.

Identifying children who miss either of these predicts 52.4% of those who miss the preschool booster.

Conclusion-Effective targeting of children who have missed previous immunisations could improve preschool booster uptake and ensure maximum uptake of at least one dose of measles, mumps, and rubella vaccine.